Diverse content is another thing Kendrick has over Nas definitely
Nah.
One of Nas most celebrated attributes is his willingness to explore a variety of concepts and topics. Heck sometimes he gets criticized for being too "out there" and experimenting too much...to the point that he gets accused of having contradictory feelings, thoughts, and topics in his music. Just examining his religious thoughts in his music alone will produce a ton of viewpoints.
Just off the top of my head, songs that are different from each other in significant ways.
Daughters
Rewind
Fetus
Testify
Dance
Project Roach
Bye Baby
These Are Our Heroes
Fried Chicken
Drunk By Myself
Purple
Dr. Knockboot
Doo Rags
If Heaven Was A Mile Away
Accident Murderers
Undying Love
Sekou Story
One Love
I Can
Sly Fox
Black Girl Lost
Remember The Times
Who Killed It
Last Words
I Gave You Power
War
What Goes Around
UBR
Book of Rhymes
No Ideas Original (super relevant to the topic)
Bridging The Gap
Surviving The Times
Last Real nikka Alive
Makings of a Perfect bytch
I really could keep going.
Note, I'm not saying he always executes all of his ideas to perfection. But that's not the point. His catalogue is full of diverse material, much more than what Kendrick has provided so far - which isn't a knock to Kendrick.
Nas has been around for damn near 25 years. And for 25 years he has been writing intimate feelings about his wife, children, career choices, mistakes, and accomplishments. Im not sure we've had a discography that is so transparent through so many years. The subject is himself but the specific topics and emotions touched upon have been extremely diverse.